Object localization within a physical space (e.g., a box in a warehouse) has generally involved manually tracking the object. For example, such manual tracking can include scanning a location barcode when storing or moving the object in the warehouse. Attempts to automate object localization have included using radio-frequency identification (RFID) systems. RFID systems generally employ one or more RFID readers that wirelessly interrogate one or more RFID tags. RFID tags can be passive, battery-assisted passive, or active. Generally, RFID tags receiving an interrogatory signal from an RFID reader will respond with information that can be used to uniquely identify the RFID tag. RFID readers are generally designed and installed so as to cover a specified physical area (e.g., a shopping cart at a checkout register). The physical area is generally limited to a region where the RFID can reliably interrogate tags (e.g., RFID tags associated with the goods in the shopping cart). Thus, RFID systems generally perform object tracking (i.e., whether an object passed through an area) rather than object localization.